This invention relates to flanged pipe joint assemblies, and particularly to gaskets for sealing the joint between two pipes of a flanged pipe assembly.
In the construction of industrial facilities, such as pulp and paper mills and chemical plants, there is usually a need to employ pipe to convey fluids and fluid-like mixtures throughout the facility. Since these materials are typically reactive, modern practice favors the use of polyvinylchloride ("PVC"), chlorinated polyvinylchloride ("CPVC"), fiberglass-reinforced plastic ("FRP") pipe or other essentially chemically inert pipe.
The pipe used in such facilities includes flanges at the ends of the pipe sections for assembling sections of pipe together at a joint, as is commonly understood in the art. Typically, a gasket is placed between the flanges, and the flanges are forcibly held together by bolts inserted through apertures disposed in the flanges and gasket. When the flanges are forcibly drawn together by bolts disposed therethrough, uneven stress distributions around the flange tend to weaken, and ultimately break, the flanges. While PVC, CPVC and FRP pipe used in such installations have the advantage of durability in the caustic and acidic environments of the reactive materials which flow through the pipes, their flanges are particularly susceptible to breakage due to uneven stress distributions.
Accordingly, there is a need for a flanged, plastic pipe joint assembly which employs a gasket that, when the flanges are forcibly drawn together, minimizes the uneven distribution of stress around the flanges so as to minimize the likelihood of damage thereto.